let's open our 3e DMG (again, 3e, not 3.5, since I don't own those books). Could you please point me to the Planescape material found in that book Shemeska? I'll admit, I didn't look for all that long, but, perusing the index, table of contents and a couple of likely sources, I came up with nothing Planescape in nature whatsoever.
I mentioned the same thing upthread. The 3E DMG had very little to say about other planes, as best I recall.
It is the 3.5 DMG that changed this - page 147-167 summarise some of the basic ideas about planar mechanics (eg energy traits, alignment traits, etc) from the 3E MoP, and then present a glossography of the D&D cosmology informed by Planescape (eg p 160 mentions the Blood War in the entry on the Abyss).
There is also a little more than a page explaining how to write one's own cosmology. Moving somewhat tangentially to your comment, I note that this section of the book is focused a lot more on mechanical elements, or on very basic story questions, than on what I would regard as serious and important story elements. For instance (p 167):
Here's a list of features that a "typical" D&D campaign needs a cosmology to provide:
- A place for deities to reside or originate from.
- A place for fiendish creatures to originate from.
- A place for celsetial creatures to originate from.
- A place for elemental creatures to originate from.
- A way for spells that use the Astral Plane, the Ethereal Plane, or the Plane of Shadow to function.
None of these are an absolute requirement . . . You can run a campaign without deities at all . . . You can decide that fiendish and celestial creatures come from the same plane, or that all elementals come from the same swirling maelstrom.
Page 168 is a discussion of planar traits - ie the effect on action resolution of various metaphysical properties of other planes.
The only discussion of the serious story role that a cosmology might provide is found in the last paragraph on p 167:
Your cosmology can reflect your own desires for the direction you want the campaign to take. If you want to stress the struggle between good and evil, then setting up strongly aligned planes for these concepts is an excellent idea. Similarly if you want a strong conflict between organization and freedom, strongly law-aligned and strongly chaos-aligned planes are recommended.
The actual definition of a "strongly aligned" plane is given on p 149: on planes that are strongly aligned, a -2 circumstance penalty applies on all INT-, WIS- and CHA-based checks made by all creatures not of the plane's alignment.
I may be an outlier, but if I wanted to give someone advice on how to build a cosmology that stresses the struggle between good and evil, I wouldn't start by suggesting a fairly esoteric mechanical penalty that (i) will apply on certain planes that the PCs are unlikely to end up for the first N levels of the campaign, and (ii) make it easier for evil to fight evil than for good to fight evil. Rather, I'd start by addressing the sort of stuff that 4e addresses - like, how to design a cosmology that puts good and evil into play as stakes that the players, via their PCs, will have little choice but to engage with.
That's part of what I mean when I stress 4e's emphasis on the
playability of a cosmology.